The present invention relates to color coding and color marking of a light wave conductor optical (fiber) under utilization of a controllable feed for the conductor, a dyeing station, a facility for dryiing the dye that has been applied, and a take-up spool for the marked conductor.
A device of the type to which the invention pertains broadly is described, for example, in German Patent 34 07 520. Light wave conductors and optical fiber elements are used to an increasing extent in communication, particularly for long distance communication. In the following we will designate light wave conductors and fiber optic elements by the abbreviation LWC or LWC cable, whereby a "cable" is assumed to have a number, possibly a large number, of LWCs made of glass or a transparent synthetic.
LWCs are used in communication engineering to an increasing extent as replacement for metallic conductors. An LWC cable consists basically of a core assembly made of multiple optical conductors of the LWC type and the entire arrangement is jacketed in a suitable envelope or outer cover.
LWCs are advantageous over metallic conductors for a variety of reasons. Among them are that optical elements can be bent and are flexible even at small diameter and small radii. They are by themelves very small so that the cable cross-section is small and, of course, noise is drastically reduced as compared with signal conduction through metal wires. On the other hand, LWCs are relatively brittle and sensitive against tension and compression. Hence, during manufacture, particularly during the manufacture of LWC cable, they have to handled quite carefully, which, in terms of mass production, is usually a more expensive undertaking. This kind of constraint exists also for marking and otherwise identifying and color coding LWCs or LWC cables under utilization of different dyes, dye patterns, etc. The color coding and other markings are usually necessary for identifying individual LWCs in order to effect the right connection on either end.
As stated above, the German Patent 3,407,520 discloses a process of continuous color coding of a surface of such an optical and light wave conductor by running it through a particular dyeing chamber. Entrance and exit openings of that chamber are provided by means of nipples which snugly embrace the LWC when entering and leaving. The purpose thereof is to confine the dye to the dyeing chamber. These nipples, however, are, so to speak, stationary points and thus in sliding engagement with the LWCs. These nipples can readily damage the LWCs, particularly in those instances when they aare not run into and out of the dyeing chamber i nan exactly concentric fashion and as far as the restrictive nipple opening is concerned. Also oscillations can be set up and, in the case of defective equipment, these oscillations may propagate into the dying chamber, thus interfering with the color coding process. If, then, the LWC is not run straight into and through the chamber and undergoes vibrations, it is quite possible that the coding is some form or another is incomplete, possibly even false.